This invention relates generally to electronic circuits and more particularly to methods and circuits for receiving digital electronic signals.
Digital electronic signals are used to communicate digital information. This communication may be from one device to another, one integrated circuit (or chip) to another, or within an integrated circuit itself. In many of these applications, the difference between the voltage level that denotes a xe2x80x9chighxe2x80x9d (or logical xe2x80x9c1xe2x80x9d) and the voltage level that denotes a xe2x80x9clowxe2x80x9d (or logical xe2x80x9c0xe2x80x9d) has been getting smaller. Designers have chosen these smaller differentials for reasons that include: lower power supply voltages, increasing switching speed, lowering power consumption, and the use of standard bus interfaces that have defined smaller voltage differentials.
Unfortunately, these smaller voltage differentials are harder to detect, especially in the presence of noise or other non-idealities on the signal. Accordingly, there is a need in the art for improvements that help with the detection and reception of digital signals having small voltage differentials between logical levels.
A reference voltage is moved dynamically towards a voltage level of the last received value. The movement takes place over a predetermined fraction of a bit time. The amount of movement is limited so that successive logical values don""t result in an unusable reference voltage level.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.